Problem: $\overline{AC}$ is $6$ units long $\overline{BC}$ is $5$ units long $\overline{AB}$ is $\sqrt{61}$ units long What is $\cos(\angle ABC)$ ? $A$ $C$ $B$ $6$ $5$ $\sqrt{61}$
Solution: SOH CAH TOA os = djacent over ypotenuse adjacent $= \overline{BC} = 5$ hypotenuse $= \overline{AB} = \sqrt{61}$ $\cos(\angle ABC )=\frac{5}{\sqrt{61}}$ $=\dfrac{5\sqrt{61} }{61}$